Parachutes Lab

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Introduction

-Abhirath Singh 9C Parachutes Experiment Aim: 1. To determine that the surface area of a parachute can affect the time it takes to travel a calculated distance, and therefore affecting the speed at which it falls. Hypothesis: 1. The surface area of a parachute affects the time it takes to travel a calculated distance, and the speed at which it falls. 2. Parachutes with a larger surface area will fall slower than ones with a smaller surface area, and will also take a longer time. Background: Parachutes are used by people in order to land safely from the air. These parachutes work on the basic law of air resistance. As a parachute opens up, it causes resistance against the air, causing the person using it to slow down. There are several factors that affect the way a parachute falls. These include; weight of user, force of winds blowing against the parachute, direction of winds against the parachute, material of parachute, weather conditions and surface area of parachute. ...read more.

Middle

6) Measure the height of the person dropping the parachute. And add this height to the height measured in Step 5. 7) Hold the parachute from the center of the polythene sheet and keep it at the level of your height. 8) While holding a electronical stop watch in your hand, drop the parachute onto the place where you want your parachute to land, simultaneously starting the electronical stop watch. 9) As the parachute hits the area you wanteded it to land, stop the electronical stop watch. 10) Note down the time taken. Take minimum of 3 readings. 11) Repeat the experiment for the following dimensions: 10cm by 10cm (100 cm2), 15cm by 15cm (225 cm2), 20cm by 20cm (400 cm2) and 25cm by 25cm (625 cm2). Data: Weight of Plasticine used = 4.98 grams. Distance traveled by parachute = 3.30 meters. Data Table - 1 Attempt No. 5cm by 5cm (25 cm2) ...read more.

Conclusion

Therefore we can conclude that parachutes with a larger surface area fall more slowly and take a longer time than ones with a smaller surface area. Therefore, if a person using a parachute would want a soft and safe landing with ease, they would use a parachute with a larger surface area. Errors and Modifications: 1. The square cut out of polythene were not exactly a square. 2. While the parachute was traveling, there could have been air blowing from any of the directions, causing a change in the time taken by the parachute, and therefore its speed. 3. As the steps are not level, the parachute may not have landed one or two steps lower, making it travel a longer distance, causing a change in the time taken by the parachute, and therefore its speed. 4. If the parachute was folded a little more than another, it would take longer to open up, causing a change in the time taken by the parachute, and therefore its speed. ...read more.

1.58m/s 650mm by 650mm 4500 mils 3.38 1.33m/s Anaylisis My results clearly show how the suface area of the canopy of the parachute affects the speed at which the object falls. I can see that as the surface area increases the speed at which the parachute falls decreases and the time it takes to fall increases.

For our preliminary work we established what height we should drop the parachute from. We tried dropping the parachute from the height of the table top and found that the time it took to fall to the ground was too short to be accurate.

Eventually the force of air resistance (the upward force) becomes large enough to balance the force of gravity (the downward force). The change in velocity terminates as a result of the balance of forces. At this time the net force is 0 N. Newton's first law tells us that objects will not accelerate if the net force is 0N.

Permanent set is due to the ~plasticity~ of the material. A perfectly plastic substance would have no elasticity and the smallest forces would cause a set. Lead and moist clay are nearly plastic and wood possesses this property to a greater or less extent.